It takes a particularly arrogant and ignorant leader to antagonise people whose help and co-operation he is going to need. But David Cameron is that man.

If the polls are right and he becomes Prime Minister next year, he is going to have to work with other European leaders on a whole range of vital issues.

These include boosting the economy, climate change, migration, energy supply, trade and international crime, not to mention reform of the European Union.

But Mr Cameron, by walking out of the biggest group in the EU and allying himself with a small band of fringe right-wingers, has cut off himself and a future British government.

And by sending a handwritten letter to the eccentric Czech president begging him not to sign the Lisbon treaty, he has infuriated other leaders, including those of France, Germany and Spain.

Even Lord Heseltine, the grand old man of the Conservative party, has warned that Mr Cameron's European views are disastrous, while the White House is dismayed at what they might mean for America's relations with the UK and EU.

So that is what a Cameron government will mean - incompetence, ignorance and hopelessness at home and abroad.